Efficacy and safety of a whole lung lavage program for artificial stone silicosis

Background: The incidence of silicosis has increased due to occupational silica exposure from artificial stone, with no treatments proven to halt or reverse the disease. Whole lung lavage (WLL) involves the instillation of fluid into the lungs to wash out silica particles and disease-causing inflammatory cells. This study aimed to determine the feasibility, safety, and possible benefit of WLL in patients with artificial stone silicosis.

Methods: In this prospective observational study, people with progressive silicosis with ground glass predominant radiological changes underwent WLL. High resolution computed tomography (HRCT) chest, X-ray velocimetry (XV), lung function tests, forced oscillation technique (FOT), and cardiopulmonary exercise tests (CPET) were performed before and six months after the procedure.

Results: Eight patients underwent WLL between June 2021 and November 2022. Five participants had an improvement in the International Classification of High Resolution Computed Tomography for Occupational and Environmental Respiratory Diseases (ICOERD) CT scores and reduction in XV regional ventilation distribution pre- and six months post-WLL. There was no difference in lung function [annualized rate of change in forced vital capacity (FVC) % predicted mean difference (MD) 1.81; 95% CI: -1.53 to 5.15, P=0.27; forced expiratory volume in 1 second (FEV1) % predicted MD -1.13, 95% CI: -5.08 to 2.83, P=0.55; diffusing capacity for carbon monoxide (DLCO) % predicted MD -2.62, 95% CI: -10.04 to 4.80, P=0.46]. There was no significant difference in CPET or FOT measurements. Following WLL, all patients experienced transient throat discomfort, one had fever and two required oral antibiotics. There were no serious adverse events.

Conclusions: WLL for artificial stone silicosis is safe in an expert centre who has experience in performing WLL in this population, and there may be limited benefit in selected patients. Further research is required to select those who will derive the most benefit.